(a) Technical Field
The present disclosure relates to a display device and a driving method thereof, and in particular, to an organic light emitting diode display and a driving method thereof.
(b) Discussion of Related Art
Recent trends toward light-weight and thin personal computers and televisions sets also require light weight and thin display devices, and flat panel displays satisfying such a requirement are being substituted for conventional cathode ray tubes (CRT).
The flat panel displays include a liquid crystal display (LCD), field emission display (FED), organic light emitting diode (OLED) display, plasma display panel (PDP), and so on.
Generally, an active matrix flat panel display includes a plurality of pixels arranged in a matrix and displays images by controlling the luminance of the pixels based on given luminance information. An OLED display is a self-emissive display device that displays image by electrically exciting light emitting organic material, and it has low power consumption, wide viewing angle, and fast response time, thereby being advantageous for displaying motion images.
A pixel of an OLED display includes an OLED and a driving thin film transistor (TFT) including polysilicon or amorphous silicon.
An OLED and an amorphous silicon driving transistor become degraded after a long-time driving, and this deteriorates the image quality of the OLED display and reduces the life time thereof.
Accordingly, several pixel circuits for reducing or compensating for the degradation of the OLED or the driving TFT are suggested. However, each of such pixel circuits includes three or more transistors and signal lines so as to decrease the aperture ratio. In addition, the degree of compensation decreases as time goes by.